Certified: The Security+ Prepcast

You can contain the threat, eradicate the malware, and recover the systems—but if you never look back, you miss the most valuable part of the incident response process. Every incident is an opportunity to get better, faster, and stronger. That’s why the lessons learned phase is so important. It’s the final stage of incident response—but also the one that sets the tone for the next incident. In this episode, we’ll walk through how to conduct post-incident reviews, how to capture lessons learned, and how to integrate those lessons into your security processes and policies.
Let’s begin with conducting post-incident reviews.
A post-incident review—sometimes called a post-mortem or after-action report—is a structured meeting or documentation process where the response team examines what happened, what was done well, what went wrong, and what should be improved next time. It’s not about assigning blame. It’s about learning, improving, and preventing repeat incidents.
The review typically includes all members of the incident response team, as well as representatives from IT, legal, HR, communications, and any affected business units. The discussion is guided by a series of questions: What was the root cause of the incident? How was it detected? How long did it take to contain? Were there delays or miscommunications? Did the response follow the documented plan?
Let’s walk through a real-world example. A logistics company experiences a credential-stuffing attack that leads to several customer account compromises. After the incident is resolved, the response team conducts a post-incident review. They discover that while the detection and containment steps were solid, communication with affected customers was delayed because no one had clear authority to approve public statements. As a result, the team updates their communications plan and creates a new role in the incident response playbook for external messaging approval. The next time a security alert affects customer data, the messaging is timely, accurate, and coordinated.
The most important part of a post-incident review is documentation. Every lesson, timeline, and decision should be captured in writing and stored in a central location. This documentation should be reviewed regularly and used during training and tabletop exercises. Some organizations build a “lessons learned” database, where insights from past incidents are stored and categorized by threat type, system impact, or procedural failure.
Reviews should also cover metrics. How long did it take to detect the threat? How long to contain it? Were any steps skipped? Did the automation work as expected? Measuring performance during and after incidents allows teams to identify trends and set improvement goals. For example, reducing mean time to detect, or improving compliance with escalation procedures.
Now let’s turn to the second half of this process: integrating feedback into security processes.
Learning a lesson is great—but only if you apply it. One of the most common mistakes in incident response is failing to turn review findings into action. Too often, post-incident reports identify problems but don’t result in changes to policy, tooling, or training. That’s a missed opportunity.
Integration means using the insights from the review to update your documentation, change your configurations, enhance your tools, and retrain your people. This could include updating your incident response plan, modifying alert thresholds, improving detection logic, or refining automation playbooks.
Let’s look at a practical scenario. A law firm responds to a ransomware attack. During the post-incident review, they discover that several systems had outdated antivirus signatures and missed the initial infection. As a result, they update their patching and antivirus update schedules, integrate real-time update checks into their configuration management system, and adjust the criteria for compliance audits. Within months, a similar malware strain targets the firm—but this time, the defenses detect and neutralize it immediately. The lesson became a safeguard.
Feedback can also lead to training updates. If users consistently fall for phishing emails during an incident, that’s a sign that awareness training may be outdated or ineffective. Adjusting the training program to include real examples, more interactive content, or even simulated phishing campaigns helps reinforce the message and measure improvement over time.
Incident response lessons can also inform access control policies. If an incident reveals that too many users had unnecessary administrative rights, privilege reviews may be added to routine audits. Group memberships may be restructured, and just-in-time access may be implemented.
In more advanced environments, organizations use incident findings to improve threat intelligence integration. For instance, if an attacker used a specific domain or Internet Protocol address during an incident, that indicator of compromise can be added to blocklists or detection signatures—helping prevent the same attack from working again elsewhere.
Another example comes from the cloud. After a misconfigured storage bucket is exploited during a breach, a company updates its infrastructure-as-code templates to include tighter access policies. It also adds a security guard rail to its CI/CD pipeline that checks for public exposure before allowing deployment. These changes prevent the same mistake from recurring.
Integrating lessons learned should also involve leadership and policy. Findings that involve process failures, resource shortages, or authority gaps may require policy changes or new budget requests. Documenting the impact of those failures—and showing how they could have been prevented—gives security leaders the justification they need to secure more funding or policy support.
One final note: integration should be timely. Don’t let weeks or months pass between the review and the implementation of changes. The longer you wait, the less likely it is that improvements will be made or remembered. A good practice is to assign ownership of each follow-up item during the post-incident review. Each item should have a deadline, a responsible team, and a clear path to implementation.
To summarize, the lessons learned phase of incident response is where maturity happens. Conducting thorough post-incident reviews helps teams understand what went right, what went wrong, and how to improve. But it doesn’t end there. Those insights must be integrated into your tools, your processes, and your policies. That’s how you turn every incident—from a phishing attack to a ransomware outbreak—into a building block for a more resilient organization.
For the Security Plus exam, expect questions about the lessons learned phase, how it connects to continuous improvement, and how feedback loops influence security policies. You may be asked to match corrective actions to incident types or evaluate the completeness of a post-incident review. Review terms like after-action report, improvement plan, performance metrics, policy integration, and security awareness training—they’re all testable and highly applicable to real-world incident response.
To continue studying with us, download additional resources, and access bonus content, visit us at Bare Metal Cyber dot com. And when you're ready to pass with confidence, go to Cyber Author dot me and get your copy of Achieve CompTIA Security Plus S Y Zero Dash Seven Zero One Exam Success. It’s the most practical, complete, and focused guide for mastering every domain and earning your certification.